Drive axles include an input gear set comprised of a pinion gear in meshing engagement with a ring gear. The ring gear is attached to a differential assembly that includes a differential case supporting a plurality of differential gears associated with a differential spider. The differential gears are in meshing engagement with a pair of side gears where each side gear drives one axle shaft. The axle shafts drive laterally spaced wheels. The pinion receives driving input from a vehicle power source and drives the ring gear, which is fixed to the differential case. The differential assembly drives the axle shafts via the side gears to rotate the wheels.
In certain configurations, the carrier is equipped with a driver controlled differential lock (DCDL). The DCDL is typically controlled by an air actuated shift assembly that is mounted on the carrier. The differential lock is movable between an engaged position and a disengaged position. When in the engaged position, a shift collar is moved into engagement with the differential case to lock the axle shafts and the differential assembly together. In this condition there is no differential action between the wheels of the drive axle. To disengage the DCDL, the shift collar is moved out of engagement with the differential case and there is normal differential action between the wheels of the axle.
The air actuated shift assembly generates an air signal to move the shift collar into engagement with the differential case. To disengage the DCDL, the air pressure is removed and a single return spring biases the collar away from the differential case. If the DCDL fails to disengage when differential action is required, the carrier can fail.